Thats pretty close to the plan. I have a large mill for drilling and starting the tap straight. Maybe use 1/2 or 3/4 bolts. I mount some of my vices and now the anvil on large school bus rear drum brake drums with a peice of 10" square thick walled tube to bring it to the correct height. This makes these very heavy items really easy to roll around the shop, like rolling a barrel or slide.